Brake Hoses and Pipes

On vehicles equipped with a Bendix Type 6 Anti-lock Brake System (ABS), a Diagnostic Readout Box (DRB or DRB II) is necessary for brake system bleeding. Failure to use a DRB to bleed the system will lead to system failure. Refer to the ABS portion of this section for bleeding procedures and precautions.

It is important to use quality brake hose intended specifically for the application. Hose of less than the best quality, or hose not made to the specified length will tend to fatigue and may therefore create premature leakage and, consequently, a potential for brake failure. Note also that the brake hoses differ from one side of the car to the other and should, therefore, be ordered by specifying the side on which it will be installed.

When routing a brake hose to a vehicle, minimize hose twisting and bending.

Brake Hose

Raise the end of the vehicle which contains the hose to be repaired, then support the vehicle safely using jackstands.

If necessary, remove the wheel for easier access to the hose.

Disconnect the hose from the wheel cylinder or caliper and plug the opening to avoid excessive fluid loss or contamination.

Disconnect the hose from the brake line and plug the openings to avoid excessive fluid loss or contamination.

To install:

Install the brake hose to the brake line and tighten to the specified torque.

If installing a front brake hose, make sure the hose is routed with the loop to the rear of the vehicle.

Install the hose to the wheel cylinder or caliper using new washers, then tighten the retainer to the specified torque.

Properly bleed the brake system, then check the connections for leaks.

Remove the supports and carefully lower the vehicle.

Brake Line

There are 2 options available when replacing a brake line. The first, and probably most preferable, is to replace the entire line using a line of similar length which is already equipped with machined flared ends. Such lines are usually available from auto parts stores and usually require only a minimum of bending in order to properly fit then to the vehicle. The second option is to bend and flare the entire replacement line (or a repair section of line) using the appropriate tools.

Buying a line with machined flares is usually preferable because of the time and effort saved, not to mention the cost of special tools if they are not readily available. Also, machined flares are usually of a much higher quality than those produced by hand flaring tools or kits.

Raise the end of the vehicle which contains the hose to be repaired, then support the vehicle safely using jackstands.

Remove the components necessary for access to the brake line which is being replaced.

Disconnect the fittings at each end of the line, then plug the openings to prevent excessive fluid loss or contamination.

Trace the line from 1 end to the other and disconnect the line from any retaining clips, then remove the line from the vehicle.

To install:

Try to obtain a replacement line that is the same length as the line that was removed. If the line is longer, you will have to cut it and flare the end, or if you have decided to repair a portion of the line, see the procedure on brake line flaring, later in this section.

Use a suitable tubing bender to make the necessary bends in the line. Work slowly and carefully; try to make the bends look as close as possible to those on the line being replaced.

When bending the brake line, be careful not to kink or crack the line. If the brake line becomes kinked or cracked, it must be replaced.

Before installing the brake line, flush it with brake cleaner to remove any dirt or foreign material.

Install the line into the vehicle. Be sure to attach the line to the retaining clips, as necessary. Make sure the replacement brake line does not contact any components that could rub the line and cause a leak.

Connect the brake line fittings and tighten to the specified torque.

Properly bleed the brake system and check for leaks.

Install any removed components, then remove the supports and carefully lower the vehicle.

BRAKE LINE FLARING

See Figures 4, 5 and 6

Use only brake line tubing approved for automotive use; never use copper tubing. Whenever possible, try to work with brake lines that are already cut to the length needed. These lines are available at most auto parts stores and have machine made flares, the quality of which is hard to duplicate with most of the available inexpensive flaring kits.

When the brakes are applied, there is a great amount of pressure developed in the hydraulic system. An improperly formed flare can leak with resultant loss of stopping power. If you have never formed a double-flare, take time to familiarize yourself with the flaring kit; practice forming double-flares on scrap tubing until you are satisfied with the results.

The following procedure applies to the SA9193BR flaring kit, but should be similar to commercially available brake-line flaring kits. If these instructions differ in any way from those in your kit, follow the instructions in the kit.

Fig. Fig. 4: Use the special brake line flaring tool to flare the end of the line-make sure that the fitting is already installed on the tube

Fig. Fig. 5: It is very important to cut the tubing on a 90° angle-this helped ensure an even flaring of the tube

Fig. Fig. 6: Make sure of the type of flaring needed for your vehicle before purchasing or renting the flaring tool

Determine the length necessary for the replacement or repair and allow an additional
1
/
8
in. (3.2mm) for each flare. Select a length of tubing according to the repair/replacement charts in the figure, then cut the brake line to the necessary length using an appropriate saw. Do not use a tubing cutter.

Square the end of the tube with a file and chamfer the edges. Remove burrs from the inside and outside diameters of the cut line using a deburring tool.

Install the required fittings onto the line.

Install SA9193BR, or an equivalent flaring tool, into a vice and install the handle into the operating cam.

Loosen the die clamp screw and rotate the locking plate to expose the die carrier opening.

Select the required die set (4.75mm DIN) and install in the carrier with the full side of either half facing clamp screw and counter bore of both halves facing punch turret.

Insert the prepared line through the rear of the die and push forward until the line end is flush with the die face.

Make sure the rear of both halves of the die rest against the hexagon die stops, then rotate the locking plate to the fully closed position and clamp the die firmly by tightening the clamp screw.

Rotate the punch turret until the appropriate size (4.75mm DIN) points towards the open end of the line to be flared.

Pull the operating handle against the line resistance in order to create the flare, then return the handle to the original position.

release the clamp screw and rotate the locking plate to the open position.

Remove the die set and line, then separate by gently tapping both halves on the bench. Inspect the flare for proper size and shape.

If necessary, repeat the procedure for the other end of the line or for the end of the line which is being repaired.

Bend the replacement line or section using SA91108NE, or an equivalent line bending tool.

If repairing the original line, join the old and new sections using a female union and tighten.